Tetrahydrocarbyl phosphonium salts

ABSTRACT

Novel advanced epoxy resins are prepared using phosphine or phosphonium salt initiators bearing at least one hydroxyphenyl or thiophenyl groups. These phosphonium salt initiators are novel compositions of matter. The resulting resins contain reduced quantities of extractable phosphorus containing moieties.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of application Ser. No. 515,824, filed July 21,1983, now U.S. Pat. No. 4,477,645.

BACKGROUND OF THE INVENTION

This invention relates to novel tetrahydrocarbyl phosphonium salts andthe use of these and other salts to prepare novel epoxy resins. Moreparticularly, the resulting resins incorporate the phosphonium salts orderivatives thereof.

Epoxy resins have long been produced by the reaction of a vicinalepoxide with a compound bearing phenolic hydroxyls in the presence of acatalyst in a so-called advancement reaction. A variety of catalystshave been reported in the art, including tertiary amines, quaternaryammonium halides, phosphonium halides, phosphonium carboxylates and thelike. Processes for using these catalysts, as well as stoichiometricreagents, have been detailed in U.S. Pat. Nos. 2,216,099; 2,633,458;2,658,855; 3,377,406; 3,477,990; 3,547,881; 3,547,885; 3,569,374;3,694,407; 3,738,862; 3,948,855; 4,048,141; 4,177,216 and 4,302,574.Canadian Pat. No. 893,191, German Patent DT Nos. 2,206,218 and2,335,199, the texts Handbook of Epoxy Resins by H. Lee and K. Neville,McGraw-Hill (1967) and Epoxy Resins Chemistry and Technology, edited byC. A. May and Y. Tanaka, Marcel Decker, Inc. (1973) are also ofinterest.

The use of certain phosphonium trifluoroacetate salts as advancementcatalyts for epoxy resins is disclosed in U.S. patent application Ser.No. 391,094, filed June 23, 1982. It is disclosed therein that thesephosphonium salts may bear hydroxyphenyl or thiophenyl moieties. Itshould be noted that the hydroxyphenyl and thiophenyl were proposed byone of the inventors of the instant invention common to theabove-identified application.

In general, the prior art catalysts or derivatives thereof can beextracted from the resulting epoxy resin product. In certainapplications the presence of an extractable salt is undesirable.Accordingly, it would be desirable to prepare advanced epoxy resincompositions which contain reduced quantities of extractable residuefrom the catalyst.

SUMMARY OF THE INVENTION

It has now been discovered that a trihydrocarbyl phosphine or quaternaryphosphonium cation each of which bear on the average per molecule morethan one moiety corresponding to the formula ##STR1## wherein Z is --O--or --S--, R³ at each occurrence is independently, an inert substituentother than --H, e.g., C₁ to C₄ alkyl or --Cl or --Br, and w is aninteger from 0 to 4, promote the reaction of polyepoxides withpolyhydric phenols, thiophenols, carboxylic acids or acid anhydrides;yet these phosphorus compounds are not readily extracted from theresulting resins. By the term inert substituent is meant a substituentinert in the instant reaction. Preferably, less than 25 weight percentof the phosphorus compounds initially present in the resulting resin areextracted in refluxing methanol in 12 hours.

The aforementioned phosphinophenols, phosphinothiophenols andquaternized derivatives thereof are incorporated into the resultingresins via reaction with the epoxides. Inasmuch as these phosphoruscompounds undergo reaction with epoxides in the subject process, theyare referred to herein as initiators rather than catalysts. The resinsincorporating moieties derived from these phosphorus compounds are alsobelieved novel.

DETAILED DESCRIPTION OF THE INVENTION Phosphinophenols,Phosphinothiophenols and Quaternary Derivatives

Preferred phosphorus-containing initiators correspond to one of thefollowing formulae I, II and III: ##STR2## wherein R and R² are eachindependently ##STR3## or monovalent hydrocabon radicals, X.sup.⊖ is acompatible anion, R¹ is a monovalent hydrocarbon radical optionallyincluding chlorine, bromine, phosphine, phosphonium, phenyl andthiophenyl moieties, Z is independently --O-- or --S-- at eachoccurrence, and A is a hydrocarbon radical bearing valences on one ormore carbon atoms equal in total to (n+1), where n is an integer 1, 2 or3.

The compounds of formula II are believed novel. Likewise, the compoundsof formula III are believed novel. The compounds of formula I wherein Zis --S-- are also believed novel.

These salts of formulae II and III can also be novel zwitterions, i.e.,the anion is formed by deprotonation of one of the ##STR4## groups. Inone preferred embodiment of the invention the initiator corresponds tothe formula ##STR5## wherein m is an integer from 1 to 3, preferably 1to 2.

Preferred initiators correspond to formulae I, II or III presentedhereinbefore. Particularly preferred are compounds wherein R and R² areeach independently phenyl, thiophenyl or hydroxyphenyl; R¹ is phenyl orC₁ to C₄ alkyl; A is an (n+1)-valent alkyl radical having 1 to 12 carbonatoms; n is 2; w is 0, and X.sup.⊖ is fluoride, bromide, chloride,iodide, carboxylate (such as acetate), bicarbonate, biphosphate, phenateor bisphenate anion. Preferably, each initiator bears a total of twohydroxyphenyl or thiophenyl moieties. Initiators bearing only onehydroxyphenyl or thiophenyl group produce resins of low molecularweight, whereas those bearing more than two such groups producecross-linked resins when employed at high concentrations. Mostpreferably, Z at each occurrence in formulae I, II and III is --O--.

These initiators in general can be prepared by techniques known in theprior art. For example, Senear et al, J. Org. Chem., 25, pp. 2001-2006(1960), describe the preparation of certain compounds corresponding toFormula I and II.

Preferred compounds of Formula III can generally be prepared by thefollowing reaction: ##STR6## wherein q is an integer from 1 to 20 andthe catalyst can be BF₃.

The compounds of formula III can also generally be prepared by thefollowing reaction: ##STR7## wherein q is an integer from 1 to 20 and Tis Cl or Br. Anion exchange is possible to produce salts with otheranions.

Still other compounds of formula III can typically be prepared by thefollowing reaction: ##STR8## wherein q and T are as describedhereinbefore.

The aforementioned reactions are in general conducted neat or indiluents inert in the subject reactions. Preferred as diluents arearomatic hydrocarbon, e.g., xylene. Temperatures from about 25° to about180° C. are in general suitable for the preparation of the subjectinitiators.

One of ordinary skill in the art familiar with G. M. Kosolapoff et al,Organic Phosphorus Compounds, Vols. 1 and 2, Wiley-Interscience (1972)can readily devise methods of producing other initiators.

The phosphinophenols and their quaternary derivatives are generallywhite or light-yellow crystalline solids. These solids are generallysoluble or slightly soluble in moderately polar solvents.

General Utility:

The subject initiators can be reacted with vicinal epoxide reactants inthe same manner as other phenol or thiophenol reactants, except thatthese initiators do not require a separate catalyst when used atcatalytically effective loadings. In preferred embodiments of thisinvention, other polyhydric phenols not containing phosphorus moietieswould be reacted with the epoxide present at the same time as theinitiators.

Epoxy Reactants:

The most useful epoxides for reaction with the subject initiators arethe polyepoxides, particularly epoxy resins. These polyepoxides arereacted with polyhydric phenols (compounds having more than one phenolichydroxy group) to form a phenolic hydroxy ether in a so-calledadvancement reaction. The polyepoxide reactants are organic compoundspossessing more than one 1,2-epoxide group per molecule. Thesepolyepoxides can be saturated or unsaturated aliphatic orcycloaliphatic, aromatic or heterocyclic in nature. Additionally, thepolyepoxides can bear substituents which are inert in the advancementreaction, such as ether or halogen moieties.

The polyepoxides are conveniently described in terms of epoxy equivalentvalues, as defined in U.S. Pat. No. 2,633,458. The polyepoxides used inthe subject advancement reaction are those having an epoxy equivalencygreater than 1.0.

Various examples of polyepoxides that may be used in the invention aregiven in U.S. Pat. No. 2,633,458 and it is to be understood that so muchof the disclosure of that patent relative to examples of polyepoxides isincorporated by reference into this specification.

Other examples of polyepoxides include the glycidyl ethers of novolacresins, i.e., phenol-aldehyde condensates. Preferred resins of this typeare those of the formula IV: ##STR9## wherein each R⁴ independently ishydrogen or an alkyl radical and j has an average value of from about0.1 to about 10, preferably from about 1 to about 2. Preparation ofthese polyepoxides is illustrated in U.S. Pat. Nos. 2,616,099 and2,658,885.

The preferred polyepoxides are those represented by the general formulaV: ##STR10## wherein R₅, R₆, R₇ and R₈ are each independently selectedfrom hydrogen, bromine, chlorine and --CH₂ CH═CH₂ and wherein Y isselected from oxygen, sulfur, --SO--, --SO₂ --, bivalent hydrocarbonradicals containing up to about 10 carbon atoms, oxygen-, sulfur- andnitrogen-containing hydrocarbon radicals, such as --OR'O--,--OR'--O--R'--O--, --S--R'--S--, and ##STR11## wherein R' is a bivalenthydrocarbon radical at each occurrence. "Y" preferably is an alkylene oralkylidine group having from about 1 to about 4 carbon atoms. In anotherpreferred embodiment, "Y" is derived from the initiators correspondingto formulae I, II or III.

Other examples of polyepoxides include the epoxidized esters of thepolyethylenically unsaturated monocarboxylic acids, such as epoxidizedlinseed, soybean, perilla, oiticica, tung, walnut and dehydrated castoroil, methyl linoleate, butyl linoleate, ethyl 9,12-octadecanedioate,butyl 9,12,15-octadecanetrioate, butyl oleostearate, mono- ordiglycerides of tung oil, monoglycerides of soybean oil, sunflower oil,rapeseed oil, hempseed oil, sardine oil, cottonseed oil, and the like.

Other epoxy-containing reactants useful in the disclosed process areobvious to one of ordinary skill in the art. Such reactants aredescribed in U.S. Pat. No. 4,302,574, which is incorporated herein byreference.

Sulfur analogs of glycidyl ether groups, i.e., compounds bearing##STR12## are also operable. For example, ##STR13## can be used in placeof an epoxide reactant.

Phenolic and Thiophenolic Reactants:

The phenolic and thiophenolic reactants are organic compounds having oneor more hydroxyl or thiol groups attached to an aromatic carbocyclicnucleus. This class of compounds therefore includes thiophenol, phenol,alpha and beta naphthol, o-, m-, or p-chlorophenol, alkylatedderivatives of phenol (e.g., o-methyl-, 3,5-dimethyl-, p-t-butyl- andp-nonylphenol) and other monohydric phenols as well as polyhydricphenols, and as resorcinol, hydroquinone, dithiophenol,p,p'-dimercaptophenyl ether, p,p'-dimercaptobiphenyl,p-hydroxythiophenol, etc.

Mixtures of phenolic and thiophenolic reactants can be employed.However, phenolic reactants are generally preferred.

The polyhydric phenols bearing from 2 to 6 hydroxyl groups and havingfrom 6 to about 30 carbon atoms are particularly useful as reactants inthe reaction with epoxy resins to form high molecular weight resins.Representative of these preferred phenols are2,4',4"-tri(hydroxyphenyl)methane, phenolphthalein and the like.Particularly preferred as phenol reactants are those compoundscorresponding to formula V. The most preferred phenols are bisphenol A(4,4'-isopropylidenediphenol), bisphenol F (4,4'-methylenediphenol),2,2',6,6'-tetrachlorobisphenol A, 2,2',6,6'-tetrabromobisphenol A,bisphenol S (4,4'-sulfonyldiphenol), 4,4'-dihydroxybiphenyl and2,2'-diallyl bisphenol A. Bisphenol A is the polyhydric phenol ofchoice.

The subject phosphorus-containing initiators are themselves phenolic orthiophenolic reactants. These initiators comprise up to 100 mole percentof the total phenolic and thiophenolic reactants present, preferablycomprise no more than about 10 mole percent of these reactants.

The Carboxylic Acid Reactants:

The organic carboxylic acids and anhydrides are likewise well known. Theacids bear one or more carboxyl groups on the organic nucleus. Theanhydrides are prepared from such carboxylic acids by the removal ofwater therefrom in an intra- or intermolecular condensation. This classof compounds therefore includes acetic, propionic, octanoic, stearic,acrylic, methacrylic, oleic, benzoic, phthalic, isophthalic, maleic,succinic, adipic, itaconic, polyacrylic and polymethacrylic acids, andthe like, and anhydrides thereof, such as acetic anhydride, phthalicanhydride, hexahydrophthalic anhydride, etc.

A preferred subclass of acids is comprised of members which are usefulin cross-linking epoxy resins. The members of this subclass are normallydi- or tribasic acids, or anhydrides thereof, and are preferably liquidor low melting solids such as succinic, maleic, or hexahydrophthalicacids or anhydrides and the like. Other such acids and anhydrides areshown, for example, in U.S. Pat. Nos. 2,970,983 and 3,547,885.

Typically, resins prepared from the reaction of epoxides with phenols orthiophenols have more diverse utilities than those prepared fromcarboxylic acids or anhydrides.

Process for Reacting Epoxide and Phenol:

The reaction conditions employed in the process may be varied.Generally, however, convenient rates of reaction are obtained atreaction temperatures in the range of from about 50° C. to about 300° C.and reaction pressures ranging from about subatmospheric (0.1 millimeterHg) to about 150 psig.

The ratio of the epoxide to the phenol, thiophenol or carboxylic acid oranhydride reactants to be employed in the process may vary over a widerange depending upon the type of reactants and the type of productdesired. For example, if a product terminated with a phenolic hydroxylgroup is desired, one would employ an excess of the polyhydric phenol inthe process.

The amount of the phosphorus-containing initiator employed in theprocess of this invention can likewise vary over a wide range, so longas an effective amount is present. In general, the initiator is added inamounts of at least about 0.01 percent, preferably from about 0.1percent to about 10 percent, by weight of the other reactants.

The reaction may be conducted in the presence or absence of solvents ordiluents, but is conveniently conducted in a liquid phase. In mostcases, the reactants will be liquid or low melting solids and thereaction may be at least initially easily effected without the additionof solvents or diluents. As the advancement reaction proceeds and theaverage molecular weight of the product increases, the reaction mixturebecomes progressively more viscous and may solidify. To maintainefficient blending of the reaction mixture, it may be necessary to adddiluents, increase the temperature of the reaction mixture to the fusionpoint of the reactants or to utilize very efficient blending means.Suitable diluents are those organic compounds which are inert to thereactants and in the liquid phase at the reaction temperature, forexample, ethylene glycol ethyl ether, xylene, toluene, cyclohexane andthe like. The diluent is desirably substantially free of impuritieswhich will decrease the activity of the catalyst, such as hydrogenperoxide or uncomplexed transition metal ions and moieties which reactwith phosphonium ylids, e.g., water, aldehydes and ketones.

If solvents are employed in the reaction and the resulting product is tobe used for coating purposes, the solvent may be retained in thereaction mixture. Otherwise, the solvent can be removed by any suitablemethod such as distillation and the like.

Desirably, substantially equivalent quantities of polyhydric phenol (orthiophenol) and polyepoxide reactants should be employed in the overallreaction (i.e., no more than about 2 percent excess of either reactant).As the reaction between the polyepoxide and the polyhydric phenolapproaches completion, it is desirable, but not essential, to introducesufficient tetrabromobisphenol A to react the vicinal epoxy groupscompletely and to increase molecular weight of the product in the mannertaught in U.S. Pat. No. 4,104,257.

Advancement Reaction Products:

The products obtained by reacting a polyepoxide with a phenol in thepresence of the described initiators are phenolic hydroxy ethercompounds. Their physical characteristics will depend upon the reactantsand proportions employed. In general, the products will vary fromliquids to solids, and in the case of the high molecular weight resinswill vary from viscous liquids to hard solids. The products will possessan aliphatic OH group formed by each reaction of an epoxide and aphenolic OH group, and can be further reacted through this group ifdesired. The polyfunctional reactants will also give products terminatedin phenolic OH groups and/or epoxy groups, and these will be availablefor further reaction. For example, if the initiator bears more than twoaromatic hydroxyl groups, the product will have branched or cross-linkedstructure.

The control of the equivalent ratio of the polyepoxides and polyhydricphenols during the advancement reaction permits the preparation of avariety of products. Those products which use an excess of thepolyepoxide in their preparation will be terminated in epoxy groups andcan be used as polyepoxides in known reactions of polyepoxides withcuring agents and the like. The high molecular weight polyepoxides areparticularly useful in preparing surface coatings, adhesives, laminates,filament windings, coatings for highways and airfields, structuralappllications, formation of foams and the like. Those prepared from thehalogenated polyhydric phenols or containing a large weight percentageof phosphorus moieties are particularly useful as flame-proofing resinsfor forming laminates coatings and the like.

If the advanced resins are prepared under essentially anhydrousconditions (eliminating essentially all water from the reactants) and attemperatures less than about 170° C., the phosphorus moieties thoughpolymer-bound retain catalytic activity. The reaction conditions arefurther described in U.S. patent application Ser. No. 470,107, filedFeb. 28, 1983. These resins exhibit accelerated curing with amines andanhydrides.

Resins prepared at higher temperatures or in the presence of water willgenerally contain phosphorus moieties present as polymer-bound tertiaryphosphine oxides or phosphonium cations. These moieties exhibit littlecatalytic activity but improve ignition retardance of the resin.

The reaction products terminated in epoxy groups can also be used toprepare vinyl ester resins. Vinyl ester resins are described in U.S.Pat. No. 3,367,992 wherein dicarboxylic acid half esters of hydroxyalkylacrylates or methacrylates are reacted with polyepoxide resins. Bowen inU.S. Pat. Nos. 3,066,112 and 3,179,623 describes the preparation ofvinyl ester resins from unsaturated monocarboxylic acids such as acrylicand methacrylic acid. Vinyl ester resins based on epoxy novolac resinsare described in U.S. Pat. No. 3,301,743 to Fekete et al. Fekete et alalso describe in U.S. Pat. No. 3,256,226 vinyl ester resins wherein themolecular weight of the polyepoxide is increased by reacting adicarboxylic acid with the polyepoxide resin as well as acrylic acid,etc. Other difunctional compounds containing a group which is reactivewith an epoxide groups, such as an amine, mercaptan, and the like, maybe utilized in place of the dicarboxylic acid. All of theabove-described resins, which contain the characteristic linkages##STR14## and terminal, polymerizable vinylidene groups, are classifiedas vinyl ester resins, and are incorporated herein by reference.

The unsaturated monocarboxylic acids which can be reacted with apolyepoxide in the presence of the described catalysts to prepare avinyl ester resin include acrylic acid, methacrylic acid, halogenatedacrylic acid or methacrylic acid, cinnamic acid and the like andmixtures thereof, and hydroxyalkyl acrylate or methacrylate half estersof dicarboxyl acids as described in U.S. Pat. No. 3,367,992 wherein thehydroxyalkyl group preferably has from 2 to 6 carbon atoms.

The products prepared by the reaction of epoxides with thiophenols aregenerally similar in properties and utilities to those prepared fromphenols. Typically, the thiophenol-derived resins exhibit highermolecular weights than their phenolic counterparts.

The following examples are illustrative of the subject invention and arenot to be construed as limiting the scope thereof. All parts andpercentages are by weight unless otherwise indicated. For the purposesof these examples, the theoretical epoxide content has been calculatedneglecting the reaction of the initiator as a phenolic reactant. Theinclusion of the initiator as a phenolic reactant in these calculationswould increase the theoretical epoxide content slightly, typically about0.1 percent (e.g., 8.1% instead of 8.0%).

EXAMPLE 1

Magnesium turnings (9.72 gram (g), 0.4 mole) were placed in a 1-liter,3-neck, round-bottom flask equipped with a condenser and drying tube(CaCl₂), addition funnel, magnetic stirrer, and N₂ bubbler. The assemblywas flame-dried using a Bunsen burner with a constant stream of dry N₂passing through the vessel. Upon cooling to room temperature, 200 mlabsolute ether was added, followed by dropwise addition ofp-bromoanisole (74.8 g, 0.4 mole) over 30 minutes. When the reactionbegan to effervesce, it was partially cooled in a salt/ice bath. After 2hours only traces of magnesium remained and the solution was cooled to-10° C. Phosphorus trichloride (18.3 g, 0.13 mole) in 70 ml ether wasthen added over 2 hours. The solution was allowed to warm to roomtemperature overnight, diluted with 300 ml dry toluene, and the etherdistilled off. This solution was cooled to 0° C. and NH₄ Cl (25 g in 100ml H₂ O) was added. After 2 hours the toluene layer was separated, driedover MgSO₄, filtered, and solvent removed on a rotary evaporator leavingan oil that quickly solidified. Recrystallization from absolute ethanolgave 19 g (47%) white rosettes which were confirmed by conventionalanalytical techniques to be tri(p-methoxy)phenylphosphine (m.p.126°-128° C.). NMR (CD₃ OD); δ(ppm, TMS) 3.60 (s, 3H, CH₃), 6.9-7.6 (m,4H, aromatic).

To 30 ml 48% HBr in a 50 ml round-bottom flask was added 1 gram (0.0033mole) of tri(p-methoxyphenyl)phosphine. The homogeneous solution washeated to reflux (124° C.) under a stream of N₂ (to remove CH₃ Br) andwithin 40 minutes a white precipitate formed. After 2 hours reflux, themixture was filtered, washed with water, and vacuum dried to give 1.11 g(98%) tri(p-hydroxyphenyl)phosphine hydrobromide.

This hydrobromide salt was stirred in 10 ml 3% NaOH for 1 hour at roomtemperature. Dry ice (CO₂) was added to neutralize excess NaOH and aprecipitate quickly formed. This mixture was extracted with 3×50 mlabsolute ether, dried over MgSO₄, filtered, and ether was removed on arotary evaporator leaving 0.88 g of tri(p-hydroxyphenyl)phosphine (86%),(m.p. 128°-133° C.). NMR (CD₃ OD); δ(ppm, TMS) 6.9-7.6 (m, aromatic).

Tri(p-hydroxyphenyl)phosphine (4 g, 1.29 millimole (mmole)) was stirredin 150 ml absolute ether at room temperature in a 250 ml round-bottomflask. Methyl iodide (2.75 g, 19.4 mmol, 1.21 ml) was added, and thesolution stirred overnight. A test for unreacted phosphine in the ethersolution (maleic anhydride in acetone) was negative, and the product wasfiltered off as a white precipitate and vacuum dried at room temperatureovernight giving 5.76 g of tri(p-hydroxyphenyl)methylphosphonium iodide(98.8% yield). NMR (CD₃ OD); δ(ppm, TMS) 2.80 (d, 3H, CH₃), 6.82-7.52(m, 12H, arom.).

EXAMPLE 2

In a manner otherwise similar to Example 1, methyldi(p-hydroxyphenyl)phenyl phosphonium iodide was prepared usingphenyldichlorophosphine in place of phosphorus trichloride.

EXAMPLE 3

In a manner otherwise similar to Example 1,methyl(p-hydroxyphenyl)diphenyl phosphonium iodide was prepared usingdiphenylchlorophosphine in place of phosphorus trichloride.

EXAMPLES 4-7

Tri(p-hydroxyphenyl)phosphine hydrobromide prepared in Example 1 and theproducts prepared in Examples 2 and 3 were used to promote the reactionof bisphenol A and a commercial epoxy resin (DER-330™ epoxy resin soldby The Dow Chemical Company). To a flask equipped with a stirrer,thermometer, heating mantle and nitrogen purge line was charged 224.2grams of DER-330™ epoxy resin and 75.8 grams of bisphenol A. The mixturewas heated with stirring to 50° C. and then 0.3 or 3.0 grams of eachinitiator in 20 milliliters (ml) of methanol were added in separateruns.

The resulting reaction mixtures were heated rapidly to 150° C. at whichpoint heating was discontinued and the reaction allowed to exotherm.After the exotherm had subsided to 160° C., this temperature wasmaintained for an additional three hours. The products were poured intotrays and allowed to cool. The product from thetri(p-hydroxyphenyl)phosphine hydrobromide was very viscous at 160° C.,while the other products were free-flowing liquids.

The solid resins were analyzed via conventional methods to determine thefinal epoxide content. The theoretical epoxide content in each case was8 percent. A 150-gram sample of each resin was refluxed in methanolovernight in a Soxhlet extractor. The extract was concentrated,dissolved in ethylene glycol ethyl ether to prepare a 50 percentsolution and analyzed by phosphorus-31 nuclear magnetic resonance todetermine what percentage of the phosphorus present in the resin hadbeen extracted. The results of these experiments are tabulated in TableI:

                                      TABLE I                                     __________________________________________________________________________                                           Phosphorus                                                        Peak        Compounds                                                         Exotherm                                                                            Observed                                                                            in Extract                             Example                                                                            Initiator (%)         (°C.)                                                                        % Epoxide                                                                           (% Initial P)                          __________________________________________________________________________          ##STR15##        (1.0%)                                                                            191   5.90  None Observed                          5                                                                                   ##STR16##        (1.0%)                                                                            182   6.30  "                                      6    "                 (0.1%)                                                                            230   8.13  "                                      7                                                                                   ##STR17##        (1.0%)                                                                            205   6.93  "                                      __________________________________________________________________________

The data presented in Table I indicates that all of these initiatorseffectively promote reaction of epoxides and phenolic hydroxyls. Thephosphorus-containing residue from the initiators was not extractable.

COMPARATIVE EXPERIMENTS 1-3

In a series of comparative experiments, conventional epoxy advancementcatalysts were used in place of the initiators in reactions and testsotherwise similar to Example 4. The catalysts were all employed at aloading of 1 weight percent based on the reactants. The catalystsincluded triphenylphosphine hydrobromide, ethyltriphenylphosphoniumiodide and ethyltriphenylphosphonium acetate. The results of theseexperiments are compiled in Table II:

                                      TABLE II                                    __________________________________________________________________________                     Peak        Phosphorus                                       Comp.            Exotherm                                                                            Observed                                                                            Compounds in                                     Exp.                                                                              Catalyst     (°C.)                                                                        % Epoxide                                                                           Extract (% Initial P)                            __________________________________________________________________________    1   (Phenyl).sub.3P HBr                                                                        195   7.60  (Phenyl) .sub.3PO (100%)                         2   (C.sub.2 H.sub.5 )P.sup.⊕(Phenyl).sub.3 HC.sub.3 CO.sub.2.sup..crc        lbar..H.sub.3 CCO.sub.2 H                                                                  185   7.76                                                                                 ##STR18##                                       3   (C.sub.2 H.sub.5 )P.sup.⊕(Phenyl).sub.3 I.sup.⊖                                179   7.17                                                                                 ##STR19##                                       __________________________________________________________________________

It is apparent that phosphorus-containing compositions derived fromconventional catalysts can be extracted from epoxy resins made usingthese catalysts.

EXAMPLE 8

The solid methyl di(p-hydroxyphenyl)phenyl phosphonium iodide preparedin Example 2 was added to excess 1.0 Normal aqueous NaOH and stirred for15 minutes at 25° C. Solid dry ice was added slowly to precipitate awhite solid. This solid was determined by proton magnetic resonance andother conventional techniques to correspond to the formula ##STR20##

EXAMPLE 9

To a reaction vessel were charged DER-330 epoxy resin anddi(mercaptophenyl)ether in a ratio which in theory should produce anadvanced resin having 3.0 percent epoxide. To this mixture was added aphenyl di(p-hydroxyphenyl)phosphine initiator in a ratio of 0.5 partsper hundred resin (phr). The advancement reaction was then conducted inthe general manner of Example 4.

The resulting resin was determined to contain 2.90 percent epoxide. Nophosphorus compounds were extracted from the resin in refluxingmethanol.

EXAMPLE 10

To a reaction vessel were charged DER-330 epoxy resin anddi-3,3'-allyl-4,4'-hydroxyphenyl)isopropylidene, i.e., ##STR21## in aratio which in theory should produce an advanced resin having 8.0percent epoxide. To this mixture was added the same initiator as inExample 9 in a ratio of 0.2 part phr. The advancement reaction wasconducted in the general manner of Example 4.

The resulting resin was determined to contain 7.88 percent epoxide. Nophosphorus compounds were extracted from the resin in refluxingmethanol.

EXAMPLE 11

To a reaction vessel were charged the same epoxy resin and dihydricphenol as in Example 9 in a ratio which in theory should produce anadvanced resin containing 1.0 percent epoxide. To this mixture was addedmethyl di(p-hydroxyphenyl)phenyl phosphonium acetate in a ratio of 0.4part phr. The advancement reaction was conducted in the general mannerof Example 4.

The resulting resin was determined to contain 1.22 percent epoxide. Nophosphorus compounds were extracted from the resin in refluxingmethanol.

EXAMPLES 12-21

A series of reactions were conducted in which various polyepoxides anddihydric phenols or thiophenols were reacted in the presence of variousinitiators in accordance with the general procedure of Example 4. Theepoxide content of the resulting resin was determined as well as thepercentage of phosphorus which could not be extracted by refluxingmethanol. The reactants, initiator, percent epoxide and other parametersor results are tabulated in Table III.

                                      TABLE III                                   __________________________________________________________________________                                                             %                                                                     % Epoxide                                                                             Phosphorus           Ex-                                              Theo-                                                                             Ob- Not                  ample                                                                             Epoxide        Phenol         Initiator (phr)                                                                              retical                                                                           served                                                                            Extracted            __________________________________________________________________________    12  DER-330*                                                                                      ##STR22##                                                                                    ##STR23##     8.0 7.94                                                                              90%                                                    (0.6)                                       13  "              "                                                                                             ##STR24##     4.0 3.97                                                                              65%                                                    (0.35)                                      14  "              Bisphenol A                                                                                   ##STR25##     8.0 7.95                                                                              70%                                                    (0.35)                                      15  "                                                                                             ##STR26##                                                                                    ##STR27##     1.0 1.31                                                                              70%                                                    (0.6)                                       16  "              Bisphenol A                                                                                   ##STR28##     1.0 1.4 100%                                                   (0.06)                                      17                                                                                 ##STR29##                                                                                    ##STR30##                                                                                    ##STR31##     6.0 5.82                                                                              70%                  18  "              "                                                                                             ##STR32##     6.0 5.97                                                                              60%                                                    (0.35)                                      19                                                                                 ##STR33##     Bisphenol A    Same as in Ex. 18                                                                            N.D.                                                                              N.D.                                                                              N.D.                 20  "                                                                                             ##STR34##     "              "   "   "                    21  DER 330*       Bisphenol A    As prepared in Ex. 8                                                                         8.0 7.7 100                                                    (0.15)                                      __________________________________________________________________________     *- Trademark of The Dow Chemical Company                                      N.D. -- Not Determined.                                                  

What is claimed is:
 1. A compound corresponding to the formula ##STR35##wherein R and R² are each independently phenyl or hydroxyphenyl R¹ is aC₁ to C₄ alkyl and X.sup.⊖ is fluoride, bromide, chloride, iodide,carboxylate, bicarbonate, biphosphate, phenate or bisphenate.
 2. Acompound corresponding to the formula ##STR36## wherein R and R² areeach phenyl or hydroxyphenyl R¹ is phenyl or C₁ to C₄ alkyl A is atrivalent alkane radical having from one to 12 carbon atoms and X.sup.⊖is fluoride, bromide, chloride, iodide, carboxylate, bicarbonate,biphosphate, phenate or bisphenate.
 3. A compound corresponding to theformula ##STR37## wherein m is an integer from 1 to
 3. 4. The compoundas described in claim 3 wherein m is the integer 1 or 2.